Changes between Initial Version and Version 6 of Ticket #22546


Ignore:
Timestamp:
03/12/17 16:29:17 (5 years ago)
Author:
moritz
Comment:

Thanks for the comments, Vincent!

  • about the numbering: yes the vertices have their labeling from 0 to n-1, and also the facets of dimension P.dim()-1 have their labeling. From this it is not quite clear to me, what the best labeling for the nodes in the vertex_facet_graph would be. if labels=True, we get consistent result with the .graph method:
    sage: p = polytopes.associahedron(['A',2])
    sage: p.graph().vertices()
    
    [A vertex at (-1, 0),
     A vertex at (-1, 1),
     A vertex at (0, -1),
     A vertex at (1, -1),
     A vertex at (1, 1)]
    sage: p.vertex_facet_graph().vertices()
    
    [An inequality (-1, 0) x + 1 >= 0,
     An inequality (0, -1) x + 1 >= 0,
     An inequality (0, 1) x + 1 >= 0,
     An inequality (1, 0) x + 1 >= 0,
     An inequality (1, 1) x + 1 >= 0,
     A vertex at (-1, 0),
     A vertex at (-1, 1),
     A vertex at (0, -1),
     A vertex at (1, -1),
     A vertex at (1, 1)]
    
    The reason to have the options labels=False is basically only for internal use by the .is_combinatorially_isomorphic method.
  • typo in the description fixed
  • changed the sentence to "decide how the nodes of the graph are labelled. Either with the original vertices/facets of the Polyhedron or with integers."
  • I have no strong opinion if this method should be public or start with an underscore, I guess there are reasons for both. (Now I removed the underscore).

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  • Ticket #22546

    • Property Status changed from new to needs_work
    • Property Commit changed from to aa80ed3a21abac2b2d6b0be19c60a3d665f61e63
    • Property Dependencies changed from to #22500
    • Property Branch changed from to u/moritz/combinatorial_automorphism_group
  • Ticket #22546 – Description

    initial v6  
    1 Currently, the `combinatorial_automorphism_group` method in the polyhedron class returns the a group isomorphic to the automorphism group of the vertex-edge graph of the polyhedron. I propose to changes two the method:
     1Currently, the `combinatorial_automorphism_group` method in the polyhedron class returns a group isomorphic to the automorphism group of the vertex-edge graph of the polyhedron. I propose to changes two the method:
    22
    33 (1) don't return a permutation group on the number `1, 2,.. self.n_vertices()`, but rather a permutation group on the actual objects (vertices of the polyhedron)